Any of certain masses of gray matter in the central nervous system, as the basal ganglia.
An encapsulated collection of nerve cell bodies, typically linked by synapses, and often forming a swelling on a nerve fiber.
A centre of intellectual or industrial force, activity, etc.
A benign cystic tumour on a tendon sheath or joint capsule.
The brain; the mind.
One who spends time thinking, contemplating or meditating.
A poser; a conundrum that requires some thinking.
An intellectual, such as a philosopher or theologian.